Author(s):
Silva, I. Vieira da 
; Nogueira, Teresa ; Ascensão, Lia
Date: 2013
Persistent ID: http://hdl.handle.net/10400.9/2239
Origin: Repositório do LNEG
Subject(s): Hypericaceae ; Hypericum species
Document details
Secretory structures on the flowers of Hypericum Pubescens and H. Tomentosum
Description
Hypericum L. (Hypericaceae) is a genus represented by ca. 484 species, shrubs, perennial and annual herbs, growing widely in warm-temperate areas in Europe, West Asia and America [1]. H. perforatum (St. John’s wort), the most representative member of the genus has been used in folk medicine since Antiquity, and nowadays other Hypericum species have been incorporated in traditional medicine systems of several countries around the world. It is now well known that hypericin, pseudohypericin and hyperforin are the main compounds responsible for their therapeutic properties [2]. Although a large number of studies deal with the phytochemical and pharmacological characteristics of Hypericum species, the secretory structures that produce the bioactive compounds have only been examined in detail in a few species [3, 4, 5, 6]. Within the framework of a wider project on Hypericum glands, we have undertaken cytological studies on the flowers of H. pubescens and H. tomentosum. Here we describe the structure, development and distribution pattern of the glands present in these two Hypericum species. Flowers at different stages of development were collected from natural populations of H. pubescens and H. tomentosum, occurring in Portugal. Samples fixed with glutaraldehyde were prepared for scanning electron microscopy or embedding in Leica Historesin® for anatomy, following standard methods.
Hypericum L. (Hypericaceae) is a genus represented by ca. 484 species, shrubs, perennial and annual herbs, growing widely in warm-temperate areas in Europe, West Asia and America [1]. H. perforatum (St. John’s wort), the most representative member of the genus has been used in folk medicine since Antiquity, and nowadays other Hypericum species have been incorporated in traditional medicine systems of several countries around the world. It is now well known that hypericin, pseudohypericin and hyperforin are the main compounds responsible for their therapeutic properties [2]. Although a large number of studies deal with the phytochemical and pharmacological characteristics of Hypericum species, the secretory structures that produce the bioactive compounds have only been examined in detail in a few species [3, 4, 5, 6]. Within the framework of a wider project on Hypericum glands, we have undertaken cytological studies on the flowers of H. pubescens and H. tomentosum. Here we describe the structure, development and distribution pattern of the glands present in these two Hypericum species. Flowers at different stages of development were collected from natural populations of H. pubescens and H. tomentosum, occurring in Portugal. Samples fixed with glutaraldehyde were prepared for scanning electron microscopy or embedding in Leica Historesin® for anatomy, following standard methods.
Document Type
Conference Object
Language English
Language English
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||